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https://dev.mysql.com/doc/internals/en/handler-instantiation.html
Here is an example from the FEDERATED storage engine: ha_federated::ha_federated(TABLE *table_arg) :handler(&federated_hton, table_arg), mysql(0), stored_result(0), scan_flag(0), ref_length(sizeof(MYSQL_ROW_OFFSET)), current_position(0) {} And ...
https://dev.mysql.com/doc/internals/en/innodb-extra-bytes.html
If you're just trying to read the record, the key bit in the Extra Bytes is 1byte_offs_flag — you need to know if 1byte_offs_flag is 1 (that is, "short 1-byteoffsets") or 0 (that is, "2-byte offsets"). Given a pointer to the Origin, InnoDB finds ...
https://dev.mysql.com/doc/internals/en/libmysql-directory.html
The files here are for producing MySQL as a library (for example, a Windows DLL). The idea is that, instead of producing separate mysql (client) and mysqld (server) programs, one produces a library. The libmysql files are split into three ...Instead ...
https://dev.mysql.com/doc/internals/en/myisam-concurrent-insert.html
This, in turn, is called from ha_myisam::external_lock() from unlock_external() from mysql_unlock_tables(). To support concurrent inserts, every statement starts with copying MYISAM_SHARE::state.state to MI_INFO::save_state and lets MI_INFO::state ...
https://dev.mysql.com/doc/internals/en/myisam-dynamic-data-file-layout.html
A record can be put in one or more frames, also called the record "parts" or "blocks". The sense of the frames is to allow reusage of the space of deleted records. Starting with an empty data file, records are put in a single frame each, unless a ...
https://dev.mysql.com/doc/internals/en/optimizer-early-nulls-filtering.html
Suppose we have a join order such as this one: ..., tblX, ..., tblY, ... Suppose further that table tblY is accessed via ref or eq_ref access on tblY.key_column = tblX.column or, in the case of ref access using multiple key parts, via ... Here the ...
https://dev.mysql.com/doc/internals/en/regex-directory.html
MySQL's Monty Widenius has made minor changes in three programs (debug.c, engine.c, regexec.c) but this is not a MySQL package. MySQL calls it only in order to support two MySQL functions: REGEXP and RLIKE. One MySQL program which uses regex is ...
https://dev.mysql.com/doc/internals/en/starting-transaction-from-external-lock-method.html
MySQL calls [custom-engine.html#custom-engine-api-reference-external_lock handler::external_lock()] for every table it is going to use at the beginning of every statement. Also, if a user calls LOCK TABLES, MySQL will call handler::external_lock ...
https://dev.mysql.com/doc/internals/en/support-for-insert.html
All INSERT operations are handled through the [custom-engine.html#custom-engine-api-reference-write_row write_row()] method: int ha_foo::write_row(byte *buf) The *buf parameter contains the row to be inserted in the internal MySQL format. The ...
https://dev.mysql.com/doc/internals/en/support-for-update.html
Performing an update will depend on row format and storage implementation. Some storage engines will replace data in-place, while other implementations delete the existing row and append the new row at the end of the data file. Non-indexed storage ...